Existing penile prostheses include a first type which includes a device to manipulate blood flow within the penis. The most common device to manipulate blood flow within the penis is a ring or sleeve that applies constrictive pressure to the base of the penis to reduce blood flow through the veins which are located just beneath the skin of the penis. These rings or sleeves permit blood flow to enter the penis through the arteries of the penis, but restrict the flow of blood out of the penis. The accumulation of blood through the use of these devices results in many cases in an erection in the penis.
Prosthetic devices of this type have used various structures to apply a constrictive pressure on the penis, typically at the base of the penis proximate to the body. Some of the devices use sleeves which may be inflated with a pressurized fluid (typically air). Upon inflation, the sleeve expands inwardly to apply a constrictive pressure on the base of the penis. Many of these designs use inflatable bladders having inner and outer layers which are of unequal thicknesses and therefor unequal expansion rates. Specifically, these prostheses have thicker layers of material on the outside of the bladder than the inside of the bladder to encourage inward expansion of the bladder. Other prosthetic devices of this type have used a rigid body outside the inflatable bladder to ensure that inflation will provide inward expansion with the subsequent constriction of the penis.
This type of penile prostheses is commonly used when a decrease in blood flow within the penis occurs. Men who suffer from diabetes would be an example of those who would benefit from this type of prostheses.
For patients that have insufficient blood flow in the penis to create an accumulation of blood in the penis and create an erection in the penis, prostheses of this type are of little use.
A detrimental aspect of constricting prostheses of this type is the tissue damage that could be incurred if the prosthesis is left in place for an extended period of time. Were a user of this type of prostheses to fall asleep while wearing the prosthesis, serious injury would probably result.
Other penile prostheses do not encourage constriction of the penis. Theses prostheses are used primarily to add rigidity to the penis so that the user can engage in intercourse. The prostheses of this type, when used with the penis, simulate an erection. These prostheses are suitable for use by those who may have a diminished blood flow and may not achieve an adequate erection to engage in intercourse, as well as those who may have disease damaged tissue that prohibits an erection from occurring.
A first example of a penile prostheses of this type is shown in U.S. Pat. No. 3,939,827. This penile prosthesis uses a rigid splint which is placed against the penis and retained on the penis by a cover of flexible material. The cover is non-rigid and does not support the penis. The rigid splint has a shape to conform to the cylindrical shape of the penis.
A second example of penile prostheses that do not encourage constriction of the penis is shown in U.S. Pat. No. 5,522,787. This penile prosthesis uses a non-rigid support that is constructed of soft, elastic, resilient material such as cellular polyurethane which is cut into a panel to be wrapped around the penis. A semi-rigid stiffener may be used with the non-rigid support to enhance the resistance to bending of the prosthesis.
Both of the first and second examples of non-constricting prostheses offer somewhat adjustable sizing as the support or support cover is wrapped around the penis.
Neither of these supports allow for the adjustment of the rigidity or circumferential size of the prosthesis after it is placed on the penis. Actually, adjustment to the rigidity of either of these prostheses would require the use of a different stiffener in either of the examples, or require a different material to be used in the non-rigid support of the second example.
There is a need for a penile prosthesis which is suitable for use by those who may have a diminished blood flow and may not achieve an adequate erection to engage in intercourse, as well as those who may have disease damaged tissue that prohibits an erection from occurring. There is a need for this penile prosthesis to allow for the adjustment of the rigidity and circumferential size of the prosthesis after it is placed on the penis. This adjustment allows the prosthesis to adjust to the extent that a user may achieve an erection, as well as to adjust to the desired physical properties of the prosthesis for the sexual enjoyment of those who would use the prosthesis.